Transcript olfactory tract - Cloudfront.net

Sponge: Set up Cornell Notes
on pg. 47
Topic:
12. 4: Sense of Smell
Essential Question:
1.Where are the olfactory
receptors located?
2.Create your own example of
sensory adaptation in regards
to smell. (p. 43)
12.4 : Sense of Smell
2.1 Atoms, Ions,
and Molecules
1.Where are the olfactory receptors located?
2.Create your own example of sensory adaptation in
regards to smell. (p. 43)
Pg.46
Olfactory Organs Picture
Video Notes
•
2-5 bullets each video (x 7 videos)!!!
REVIEW: Special Senses
Location of special senses?
•Sensory receptors are within large, complex sensory
organs in the head
• Smell in olfactory organs------>olfactory receptors
3
Sense of Smell
Olfactory Receptors• Chemoreceptors- respond to chemicals dissolved in liquids.
• Similar to taste
4
How are Taste and Smell
Related?
5
Sense of Smell
Olfactory ReceptorsSmell and taste function together and aid in food selection
• 75-80% of flavor is actually the sense of smell!
6
Relationship of Taste and Smell
(1m7s)
7
Olfactory Organs
Contain:
1. Olfactory receptors
2. Supporting epithelial cells covered with hair-like cilia
• Only nerve cells in direct contact with the outside
environment
• Subject to damage
• The only neurons regularly replaced
8
Slim Goodbody: Olfactory
Organs (1m 26s)
9
Olfactory Code
Leading hypothesis• Each odor likely stimulates a distinct set of receptor cells
• The brain then recognizes the particular combination as an
olfactory code or particular smell
10
Where do you think the olfactory organs are located?
Olfactory organs located high in
the nasal cavity above the usual
pathway of inhaled air
• Sniffing and forcing air over
receptor areas may be
necessary to smell a faint odor
11
Please draw this picture on the top ½ of pg 46
Brain
*Olfactory Receptor
cells
Ethmoid
bone
12
Sensory Adaptation
How long do you think sensory adaptation occurs for the
sense of smell?
13
Sensory Adaptation
Olfactory receptors undergo sensory adaptation RAPIDLY
•
•
Sense of smell drops by 50% within a second after
stimulation
Within a minute the receptors may become insensitive to a
given odor
14
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The Chemistry of Smell (3m1s)
16
Olfactory Nerve Pathways
Once olfactory receptors are stimulated, nerve impulses travel
through…
Olfactory receptors olfactory nerves olfactory bulbs
olfactory tracts limbic system olfactory cortex
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Olfactory Nerve Pathway
Flow Map
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Odorant Molecules
•Enter nasal cavity as gases
•Dissolve partially in watery fluids that surround the cilia
•Bond to receptor proteins on cilia
19
Olfactory receptor:
•Olfactory receptor stimulated
•Generates nerve impulse!
20
Smell Receptors- Odors
Magic School Bus (2m30s)
21
Olfactory Nerves
•Contain sensory neurons located in the lining of the upper
nasal cavity
•Translate the chemical signal into the electrochemical
language of the nervous system
22
Olfactory Bulbs
•Extensions of cerebral cortex (brain)
•Sensory impulses are analyzed and sent along to olfactory
tracts
23
Olfactory Tracts
•Impulses travel along these tracts to cerebral centers of the
brain (passageway)
24
Limbic System
•Brain center for memory and emotion
•Scents bring back memories
Spilled baby powder---------> Reminds you of your child as a
25
baby
Olfactory Cortex
•Located deep in the temporal lobes
•Interpret the impulses
•You recognize the smell!
26
Essential Oils in the E.R. (3m11s)
https://www.youtube.com/watch?v=O1_1A3gRhpw
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Smell
Crash Course: A+P
6m18
• https://www.youtube.com/watch?v=mFm3yA1nslE
Pg. 47
My “smelly story”
Using your flow map, create a “story” based
on a smell encounter.
• Remember to include a description for
EACH part.
–
–
–
–
–
Odorant molecules (initial odor)
Olfactory Nerves (spark nerve impulse)
Olfactory Bulbs/Olfactory tracts (interpret and send)
Limbic System (emotion)
Olfactory Cortex (recognition)
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Ex: The Memory of my Father
• As I pass a man walking down the street, I inhale a
pleasant odor in the air (Odorant molecules).
• The scent sparks a nerve impulse in my nose.
• In an instant, my olfactory nerves translate this scent into
a chemical signal that my nervous system can understand.
• My olfactory bulbs analyze these sensory impulses and
are sent along my olfactory tract to my brain.
• As the signals pass through my limbic system, I am
reminded of memories of my father and I feel happy.
• I realize that the man I just passed was wearing the same
type of cologne that my father always wore when I was a
child. (Olfactory cortex).
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Let’s Share the Smelliest Story!
• Table Share: EVERY person must read their
“Smelly Story”
• Choose a story that best demonstrates the
olfactory nerve pathways
• Class share: Each table will share their favorite
story
– The person reading the “Smelly Story” to the class
does not need to be the person who wrote it
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